Method and apparatus for treating supracondylar fractures of the femur

ABSTRACT

Methods and apparatus for treating fractures of the distal femur are disclosed. In one embodiment, the apparatus comprises an intramedullary nail and blade. The intramedullary nail has a passage through a distal end for accepting a locking screw and a blade passage which extends through a proximal end of the intramedullary nail. In one embodiment of the invention, the apparatus includes two blades for passage through the intramedullary nail, each blade when engaging the passage being freely moveable in the passage, but both blades when engaging the passage resisting rotation thereof with respect to the nail. A blade guide, when connected to the nail, defines a passage aligned with the passage through the nail for use in forming a passage in the femur into which the blade(s) are positioned.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.09/954,676, filed Sep. 12, 2001, now U.S. Pat. No. 6,652,529.

FIELD OF THE INVENTION

The present invention relates to an apparatus for treating asupracondylar fracture of the femur, and one or more methods of treatingsuch fractures.

BACKGROUND OF THE INVENTION

One injury which may occur in humans is the fracture of the femur. Mostcommonly, femur fractures are associated with the proximal end of thefemur. These types of fractures often result in a fracture of thefemoral head from the remaining portion of the femur (known as a“femoral neck fracture”) or a fracture between the neck and shaft (knownas an “inter-trochanteric fracture”).

An injury which occurs less often, but is occurring with increasingfrequency, is a fracture of the distal end of the femur. As is known, apair of condyles are located at the distal end of the femur. Distalfemur fractures maybe classified into a variety of types with referenceto the condyles. In one class, the fracture is between the shaft of thefemur and the condyles of the femur (known as a “supracondylar”fracture). In another class of fractures, one or both condyles arefractured from the femur (known as a “condylar” or “intercondylar”fracture). In yet another class of fractures there are multiplefractures, through the supracondylar and intercondylar areas of thefemur.

A variety of treatments have evolved for fractures of the distal femur.One common method of treatment is illustrated in FIG. 1A. Illustrated inFIG. 1A is a fracture of the first type, i.e. a fracture of the femurproximal to the condyles with the condyles remaining intact. Inaccordance with one method of treatment, an exterior plate A ispositioned along the exterior of the femur. As illustrated, the plate Ahas a number of passages there through. Screws B are passed through theplate A into the femur both in the region of the condyles and an areaproximal thereto. In accordance with this form of treatment, the plateis used to secure the fractured condyles to the femur.

Other forms of the plate described above are known. For example, theplate may have an angled blade in the form of a “U”-shaped extension(see FIG. 1B), or an outwardly extending screw (see FIG. 1C). Thisangled blade or screw may be directed into the condyles, and then theother end of the plate affixed to the femur with screws.

The devices illustrated in FIGS. 1A, 1B and 1C (often termed “condylarplates”) have a number of disadvantages. One significant problem is thatthe portion of the femur distal to the fracture, i.e. the portionincluding the condyles, may rotate with respect to the device. When thecondyles are placed in a position of stress, that portion of the femurrotates both with respect to the device and the remainder of the femur.This prevents healing of the fracture or healing in an unnatural ornon-anatomically correct position.

A similar problem exists in the arrangement in FIG. 1C in that theentire screw which engages the condyles may rotate relative to theplate. Thus, even if the condyles do not rotate relative to the screw,that portion of the femur may still rotate or move relative to theremainder via rotation of the screw through the plate.

Another problem is that fixation is often made difficult when the femuris osteoporotic. In the example illustrated in FIGS. 1A, 1B and 1C,osteoporotic bone may not permit secure engagement of the screws orblade.

Yet another problem with fixation devices applied to the surface of thefemur is that the plate must endure significant cantilever moments thatmay cause the plate to break or screws to pull out of the bone. Thesemethods therefore require that the leg be immobilized and no weightborne upon the leg until the fracture has healed. For example, withreference to the prior art method and device illustrated in FIGS. 1A, 1Band 1C, the connection of the plate A and the plate itself is generallyinsufficient to adequately fix the fracture to permit the femur to bearweight. In fact, the plate and screws generally can not tolerate anysignificant load bearing at all. This again results in stresses whichincrease healing time or prevent healing, at least without othermeasures such as external bracing, immobilization or the like.

An improved method and apparatus for treating distal femur fracture isdesired.

SUMMARY OF THE INVENTION

The present invention comprises a method of treating a fracture of thedistal femur and one or more apparatus for use in a method of treating afracture of the distal femur.

In one embodiment, the invention comprises an apparatus including anintramedullary nail and a blade. The intramedullary nail is a generallyelongate member having a proximal end (nearest to the condyles of thefemur) and a distal end. Preferably, the proximal end of the nail isangled at approximately 10 degrees (in the sagittal plane when insertedin the femur) relative to the remainder of the nail to facilitateinsertion. One or more locking member accepting passages are providedthrough the distal end of the intramedullary nail.

A blade passage extends through the proximal end of the intramedullarynail. The blade passage preferably extends through the intramedullarynail at an angle of about 84-96 degrees (i.e. generally perpendicular)to an axis through that portion of the nail.

The blade also has a proximal end and a distal end. At least one of theends has a shape which is adapted to engage a portion of a femur in amanner resisting rotation of the femur with respect to the blade. In oneembodiment, the proximal and distal ends of the blade include at leasttwo generally planar surfaces which intersect at an angle.

In one embodiment, an apparatus is arranged so that the blade may befixed from moving with respect to the intramedullary nail. Fixation maybe rotational and/or axial/translational. In one embodiment, the shapeof the blade and the shape of the blade passage are configured so thatat least one surface of the blade interacts with at least one surface ofthe intramedullary nail defining the blade passage to resist or preventrotation of the blade with respect to the nail. In one embodiment, theblade passage is generally rectangular in shape and the blade is “I”shaped and sized to fit tightly within the blade passage.

In one embodiment, a locking member is provided for locking the blade tothe intramedullary nail to resist or prevent axial movement of the bladewith respect to the intramedullary nail. In one embodiment, theintramedullary nail includes a passage extending from a proximal tipthereof through the nail to the blade passage. A locking member, such asa screw, may be threaded into the passage into engagement with theblade, locking the blade to the intramedullary nail.

One or more embodiments of the invention comprise a method of treating afracture of the distal femur. One method includes the step of exposingthe distal end of said femur and then extending an intramedullary nailinto the medullary space of the femur from the distal end of the femur.Preferably, the intramedullary nail comprises an elongate member havinga proximal end and a distal end. The intramedullary nail is extendedinto the femur until the proximal end of the nail is located near thedistal end of the femur. Preferably, the intramedullary nail includes atleast one locking member accepting passage located at the distal endthereof.

The method also includes the step of positioning at least one blademember in a portion of the distal end of the femur which is distal to afracture of the femur. Preferably, the at least one blade member ispositioned generally transverse to the intramedullary nail.

The at least one blade member is fixed to the intramedullary nail togenerally prevent movement of the at least one blade member with respectto the intramedullary nail. At least one locking member is extended intothe femur and the locking member accepting passage located at the distalend of the intramedullary nail.

In one embodiment, the step of fixing the blade to the intramedullarynail comprises mating corresponding portions of the blade and bladepassage which are adapted to interfere and generally prevent rotation ofthe blade with respect to the passage. In another embodiment, the stepof fixing includes extending a screw into a passage extending inwardlyfrom the proximal end of the intramedullary nail to the blade passage.The screw is engaged with the blade, fixing the blade from axial androtational movement with respect to the intramedullary nail.

In another embodiment of the invention, the apparatus includes at leasttwo blades. The blades and passage through the intramedullary nail areshaped and size such that a single blade positioned in the passage mayfreely move, including rotate, in the passage. However, the passage andblades are configured such that when both blades are positioned in thepassage, movement of the blades, including rotation thereof relative tothe intramedullary nail, is resisted. In one embodiment, the passagethrough the intramedullary nail is generally oval in shape, while eachblade is “I”, “X” or “+” shaped in cross-section.

In accordance with the apparatus and method, an intramedullary nailprovides axial support along the length of the femur, including opposingfractured portions thereof. In addition, a blade member provides securefixation of a fractured portion of the femur relative to the remainderof the femur by engagement with the intramedullary nail. The blade isadapted to engage the fractured portion of the femur and theintramedullary nail in a manner resisting rotation. The blade is alsofixed axially with respect to the intramedullary nail. In this manner,movement of the fractured portion of the femur relative to the remainderof the femur in any plane or rotation around any axis is minimized, andhealing time is improved.

The apparatus and method of the invention provide a femur fracturetreatment which permits use of the leg soon after treatment. Theapparatus is configured to withstand high loads and fix the fracturedportion of the femur. In the region of the blade passage, theintramedullary nail is preferably enlarged, providing high strength andstiffness.

An additional aspect of the invention comprises a blade guide and amethod of using the blade guide to treat a femur fracture using the nailand blade(s) of the invention. In one embodiment, the blade guide has afirst, generally planar portion for connection to the proximal end of anail. The blade guide has a second portion having at least one passagethere through. When the blade guide is connected to an intramedullarynail located in the distal end of a femur, the second portion of theblade guide is located at the medial or lateral side of the distalfemur. The passage in the second portion of the blade guide aligns withthe blade passage through the intramedullary nail.

In use, the blade guide is connected to the proximal end of anintramedullary nail which is then placed, or already placed, in a femur.In one embodiment, the first portion of the blade guide is connected tothe nail with a screw. Because of the generally planar, thin nature ofthe first portion of the blade guide, the knee may be extended afterconnection of the blade guide.

A passage is then formed in the femur. The passage is formed using thepassage through the blade guide which is aligned with the blade passagein the nail. The passage in the femur may be formed by drilling,punching or the like. Thereafter, one or more blades may be placed intothe femur and into engagement with the intramedullary nail.

Further objects, features, and advantages of the present invention overthe prior art will become apparent from the detailed description of thedrawings which follows, when considered with the attached figures.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a fractured femur and a device for usein immobilizing the fracture in accordance with the prior art;

FIGS. 1B and 1C illustrate other devices in accordance with the priorart;

FIG. 2 is a plan view of an intramedullary nail of an apparatus fortreating a fracture of the distal femur in accordance with an embodimentof the invention;

FIG. 3 is a cross-sectional view of the intramedullary nail illustratedin FIG. 2 taken along line 3-3 therein;

FIG. 4 is a perspective view of a blade of an apparatus for treating afracture of the distal femur in accordance with an embodiment of theinvention;

FIG. 5 illustrates in partial cross-sectional view an intramedullarynail and connected blade inserted into a fractured distal femur;

FIG. 6 illustrates the assembly of FIG. 6 rotated ninety-degrees;

FIG. 7 illustrates an apparatus for treating a femur fracture inaccordance with another embodiment of the invention, the apparatusincluding an intramedullary nail and a pair of blades;

FIG. 7A illustrates the pair of blades engaging a passage of theintramedullary nail illustrated in FIG. 7;

FIG. 8 illustrates an apparatus for treating a femur fracture inaccordance with another embodiment of the invention, the apparatusincluding a locking pin;

FIG. 9 is a top plan view illustrating a blade guide in accordance withan embodiment of the invention, the blade guide illustrated attached toan intramedullary nail inserted into a femur;

FIG. 10 is a side view of the blade guide illustrated in FIG. 9;

FIG. 11 is a view of the blade guide in the direction of line 11-11 inFIG. 9;

FIG. 12 is a top plan view illustrating the correspondence between theblade guide of the invention and a blade inserted into a femur; and

FIG. 13 is a side view of the blade guide and inserted blade illustratedin FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

The invention is a method and apparatus for treating fractures of thedistal femur. In the following description, numerous specific detailsare set forth in order to provide a more thorough description of thepresent invention. It will be apparent, however, to one skilled in theart, that the present invention may be practiced without these specificdetails. In other instances, well-known features have not been describedin detail so as not to obscure the invention.

One or more embodiments of the invention comprise an apparatus fortreating a supracondylar femur fracture, otherwise known as a fractureof the distal femur. In general, the apparatus comprises anintramedullary nail for location at least partially in the femur. Theapparatus includes at least one stabilizing member for engaging aportion of the femur and the intramedullary nail. The at least onestabilizing member is adapted to cooperate with the intramedullary nailto fix fractured portions of the femur to one another. In oneembodiment, the at least one stabilizing member comprises a blade whichengages a portion of the intramedullary nail in a secure mannerpreventing axial and radial movement with respect thereto. The blade isalso adapted to engage a portion of the femur in a secure manner,preferably preventing at least rotation relative thereto.

One or more embodiments of the invention comprise a method of treating afracture of the distal femur. In one embodiment the method comprises amethod of placing the intramedullary nail in the femur, and placing theblade in the femur and securing it to the intramedullary nail.

One embodiment of an apparatus for treating a fracture of the distalfemur in accordance with the invention will now be described withreference to FIGS. 2-6. As illustrated, an apparatus in accordance withthe invention includes an intramedullary nail 20. The nail 20 isreferred to as an intramedullary nail because, as described below, atleast a portion of the nail 20 is adapted to be located within themedullary space of a femur.

In one embodiment, as illustrated in FIGS. 2 and 3, the intramedullarynail 20 comprises a rod-like member having a proximal end 22 and adistal end 24. As illustrated, the term “end” as used herein is notlimited to a terminus of the member, but more generally a regionthereof.

Referring to FIG. 3, in one embodiment the intramedullary nail 20 has agenerally circular cross-section along most of its length. At theterminus of the distal end 24, the nail 20 preferably forms a generallyhemi-spherical or bullet-shaped, smooth distal tip 25. The distal tip 25of the distal end 24 of the intramedullary nail 20 may have othershapes, but preferably is adapted to be inserted into the femur in amanner reducing the damage to the femur.

In a preferred embodiment of the invention, the intramedullary nail 20includes a blade passage 26 for accepting a stabilizing member in theform of a blade there through. Details of such a blade are providedbelow. As illustrated, the blade passage 26 is located at, and extendsthrough, the proximal end 22 of the intramedullary nail 20. Preferably,a portion of the intramedullary nail 20 about a blade passage 26 is ofan increased dimension. In one embodiment, the dimension of the nail 20is increased in a first plane there through, and not in a second planeextending generally perpendicular to the first. In a preferredarrangement, the increased dimension is in a plane which corresponds tothe sagittal plane when the nail 20 is positioned in a femur, while thenail 20 retains the same dimension in the coronal plane.

In a preferred embodiment, a substantial portion of the intramedullarynail 20 is generally straight, extending along a central axis. In apreferred embodiment, however, the nail 20 bends at an angle distal ofthe area of increased dimension. In one embodiment, the nail 20 bends atapproximately a 10 degree angle from the central axis C, extending alongan offset axis C′. As described below, the exact bend angle and locationof the bend is preferably selected to aid in insertion of the nail 20into the femur and align the nail 20 centrally along the femur.

The proximal end 22 of the intramedullary nail 20 preferably terminatesin a proximal tip 23. In one embodiment, the proximal tip 23 isgenerally planar, the plane defined by the tip positioned generallyperpendicular to the axis. Preferably, the blade passage 26 is locatedsome distance along the axis towards the distal end 24 of theintramedullary nail 20 from the proximal tip 23.

If the intramedullary nail 20 is constructed with a great length, theintramedullary nail 20 may be bent or bowed slightly to accommodate thecurvature of the femur. It is noted that when the blade passage 26 isgenerally perpendicular to the portion of the intramedullary nail 20through which it passes, then the intramedullary nail 20 may be used ineither the right or left femur even though it is provided with a bend.

The size and dimensions of the intramedullary nail 20 may vary. Ingeneral, the intramedullary nail 20 is sized to fit within the medullaryspace of a femur, extending from a distal end of the femur towards theproximal end thereof. In one embodiment the intramedullary nail 20 isapproximately 250-360 mm long from end to end. The intramedullary nail20 has a diameter of about 10-16 mm in the area excepting the enlargedportion of the proximal end 22. The intramedullary nail 20 has adiameter of about 12-20 mm in the enlarged area thereof about the bladepassage 26. The outer surface of the intramedullary nail 20 ispreferably polished smooth and burr-free. In order to provide for amaximum load carrying capability relative to the size of theintramedullary nail 20, the intramedullary nail 20 is preferably of asubstantially solid (i.e. not substantially hollow) materialconstruction.

In one embodiment, a narrow passage may be provided through theintramedullary nail 20 from the proximal tip 23 to the distal tip 25. Inthis arrangement, the intramedullary nail 20 has a cannula typearrangement permitting it to be passed along a guide wire for insertioninto a femur.

In one embodiment, means are provided for securing the distal end 24 ofthe intramedullary nail 20 to a portion of a femur in which it isinserted. In a preferred embodiment, the means includes at least onelocking member. The locking members may comprise pins or screws 28. Suchscrews 28 are well known. The screws 28 are adapted to pass throughpassages 30,32 in the intramedullary nail 20. In one or moreembodiments, the passages 30,32 are preferably spaced about 20-40 mmapart. Instead of screws, bolts having self-cutting threads may be used.One or more of the passages 30,32 may be oval or elongate in shape toallow axial sliding of the nail in the femur for compression at thefracture site. Further, the passages 30,32 may be located in thesagittal or coronal plane.

The screws 28 may have a variety of sizes. In one embodiment, each screw28 is about 30-35 mm long and about 4-6 mm in outer diameter.

As detailed above, in a preferred embodiment, at least one member isadapted to connect to the intramedullary nail 20 and engage the femur ina secure manner. In one embodiment, this member comprises a blade 34.

An embodiment of a blade 34 in accordance with the invention will bedescribed with reference to FIG. 4. In a preferred embodiment, the blade34 is arranged to engage a portion of a femur in a manner whichgenerally prevents movement of the engaged portion of the femur relativeto the blade 34. In one embodiment, the blade 34 is a generally elongatemember having a proximal end 36 and a distal end 38. As in the case ofthe intramedullary nail 20, reference to an “end” is not limited to theterminus of the blade 34, but generally includes a portion of the blade34.

In one or more embodiments, at least a portion of either or both theproximal end 36 and distal end 38 of the blade 34 has a shape designedto engage a portion of a femur and resist relative rotation of the femurwith respect to the blade 34. In a preferred embodiment, that portion ofthe blade 34 has a cross-section which is not circular or generallycircular, which does not form a helix/spiral, and which includes atleast two or more generally planar surfaces which meet at an angle.Preferably, the angle at which the planar surfaces intersect is an acuteor perpendicular angle between 20 and 90 degrees. In one embodiment, theportion of the blade 34 at which the surfaces intersect is at a maximumradial distance from the center of the blade 34, so that theintersection engages the femur when placed in a generally circular bone.

One specific embodiment of the blade 34 embodying these characteristicsis illustrated in FIG. 4. This blade 34 has a generally “I” shapedcross-section along its length. Other cross-sectional shapes may beprovided, such as “+” “X” and “T”.

The dimensions of the blade 34 may vary. In one or more embodiments, theblade 34 is about 40-60 mm long. The blade 34 has width and depthdimensions which permit it to fit within an appropriately sized andshaped blade passage.

As described in more detail below, the blade 34 is adapted to engage theintramedullary nail 20. As noted above, the intramedullary nail 20includes a blade passage 26 for acceptance of at least a portion of theblade 34 there through.

In the embodiment where the blade 34 has a generally “I” shapedcross-section, the blade passage 26 may be generally rectangular inshape, as illustrated in FIGS. 2 through 6. In one or more embodiments,as best illustrated in FIGS. 2 and 4, the blade passage 26 extendsthrough the intramedullary nail 20 at an angle α. In one embodiment, theangle α is between about 84 and 96 degrees, and more preferably 90degrees, with respect to the axis C′. In other words, the blade passage26 extends through the intramedullary nail 20 generally perpendicular(i.e. 84-96 degrees offset) to a direction along the length of the nail.It is possible for the blade passage 26 to extend through the nail 20 atgreater or lesser angles.

In a preferred embodiment, the blade passage 26 through theintramedullary nail 20 is adapted to cooperate with the blade 34 inorder to limit, if not generally prevent, movement of the blade 34 withrespect thereto at one or more times.

In one embodiment, means are provided for preventing both rotational andaxial movement of the blade 34 relative to the intramedullary nail 20.As illustrated, the means for preventing rotational movement maycomprise a configuration of the blade 34 and blade passage 26 relativeto one another. The size and shape of the blade 34 is selected withreference to the size and shape of the blade passage 26, such that oneor more surfaces of the blade 34 and blade passage 26 engage one anotherwhen an attempt is made to rotate the blade 34 relative to the bladepassage 26, preventing or limiting relative rotation thereof.

In one or more embodiments, the means for preventing axial movementcomprises at least one locking member. Referring to FIG. 3, the lockingmember may comprise at least one screw 40. As illustrated, theintramedullary nail 20 includes a passage 42 extending from the proximaltip 23 to the blade passage 26. The passage 42 is threaded. Preferably,the passage 42 extends generally parallel to, if not along, the axis C′extending through that portion of the nail 20.

The screw 40 is adapted to be inserted into the passage 42. The screw 40has external threads thereon for engaging the threaded passage 42.

A method of treating a fracture of the distal femur will now bedescribed primarily with reference to FIGS. 5 and 6. In thisdescription, reference will be made to the apparatus illustrated inFIGS. 2-4 and described in detail above.

The distal end of the femur is exposed. This may be accomplished with avariety of surgical techniques and generally occurs with the knee flexedor bent.

A bore is created in the femur. Preferably, the bore extends from thedistal end of the femur, including the portion distal of the fracture ofthe femur (such as the condyles), through the interior of the femurtowards its proximal end. The length of the bore is preferably selectedso that all or substantially all of the intramedullary nail 20 may belocated within the bore. In general, it is undesirable for the proximalend 22 of the intramedullary nail 20 to extend outwardly from the femurat its distal end once the nail 20 is placed. The intramedullary nail 20is placed in the bone. As stated above, a guide wire may be placed inthe bone and then the nail 20 passed thereover for guiding the nail 20into the bone.

The blade 34 is placed into engagement with both the femur and theintramedullary nail 20. In one embodiment, a passage or bore is formedthrough the fractured portion(s) of the femur. In a preferredembodiment, the shape of the passage or bore which is created is thesame as the cross-sectional shape (or perimeter profile) of the blade orblades which are to be positioned therein. For example, referring toFIG. 5 where the fracture is a fracture proximal to the condyles, thebore or passage is formed through the condyles. The bore extendsinwardly from an exterior surface of the femur. The bore preferablyaligns with the blade passage 26 through the intramedullary nail 20.Preferably, the bore and the blade passage 26 are co-axial, with littleor no angular offset there between. A large angular offset will preventextension of the blade 34 through the bore and blade passage 26.

The blade 34 is inserted into the bore. The blade 34 is pressed inwardlyuntil it passes through the blade passage 26. During insertion of theblade 34, the blade 34 is oriented so that it aligns with the passage26. For example, referring to FIG. 5, the blade is oriented so that itslarger height dimension aligns with the larger height dimension of therectangular blade passage 26.

The blade 34 is fully extended into the bore or passage, preferablyuntil the blade 34 does not protrude significantly from the exterior ofthe femur. Once the blade 34 is positioned, it is locked to theintramedullary nail 20. In one embodiment, the screw 40 is threaded intothe passage 42 extending into the proximal end 22 of the nail 20. Thescrew 40 is threaded inwardly until it engages the blade 34. So engaged,the screw 40 applies pressure to the blade 34, binding it against theintramedullary nail 20 within the blade passage 26.

One or more screws 28 are passed from an exterior portion of the femurinto the femur and through a corresponding passage 30,32. In oneembodiment, two screws 28 are passed through corresponding passages30,32 in the intramedullary nail 20. Locator bores may be formed in thefemur before engaging the screws 28 with the femur, thus ensuring thatthe screws engage the passages 30,32 in the nail 20. Preferably, thescrews 28 are extended into the femur until a head of the screw isgenerally flush with the exterior of the femur. In addition, the screws28 are preferably of a length that when fully engaged, a portion of eachscrew engages the femur on either side of the intramedullary nail 20.

Various configurations of apparatus other than that illustrated in FIGS.2-4 and detailed above are contemplated as within the scope of theinvention.

With respect to the fixation of the distal end of the nail 20 to thefemur, in one or more embodiments there may be provided as few as one ormore than two screws 28 or other means for attaching or securing theintramedullary nail 20 to the femur. For example, three passages may beprovided through the intramedullary nail 20 for accepting three screwsfor securing the intramedullary nail to the femur. In one or moreembodiments, the holes for accepting the one or more screws 28 can be incoronal, sagittal, or a combination of such planes with respect to thefemur and intramedullary nail.

In one or more embodiments, additional means may be used to connect thenail 20 to the femur. For example, as illustrated in FIG. 6 theintramedullary nail 20 may be provided with one or more additionalpassages or bores 44 for accepting screws or other locking members.

The cross-section of the intramedullary nail 20 may be other thancircular. For example, in one embodiment the cross-section of theintramedullary nail 20 may be oval in one or more areas. In oneembodiment, the cross-section of the intramedullary nail 20 may becircular except in the enlarged area about the blade passage 26, whereinthe cross-section is generally oval.

The means for securing the blade 34 to the intramedullary nail 20 may beother than that described above. For example, more than one screw may beuse to secure the blade 34 to the intramedullary nail 20 to preventaxial movement thereof. Other means may be provided for securing theblade 34 to the intramedullary nail 20. For example, the means maycomprise a pin which may engage the intramedullary nail in a locked andan unlocked position (such as by rotation where a catch on the pinengages a portion of the nail). In one embodiment, a pin or similarmember may be arranged to extend into the intramedullary nail and alsoall or a portion of the blade. In this arrangement, the blade may beprovided with closely spaced indentations or passages or an oblongpassage which may be aligned with the passage 42 in the intramedullarynail.

The blade 34 may be configured other than as illustrated. In oneembodiment, only the proximal and distal ends 36,38 of the blade 34, orportions thereof, are configured to resist rotation when located in thefemur. A portion between the ends 36,38 of the blade 34 may have aconfiguration which varies from the ends. For example, a portion of theblade 34 between its ends 36,38 which is positioned within the bladepassage 26 when the blade 34 is engaged with the nail 20 may have acircular or other cross-section. In that event, rotation and axialmovement of the blade 34 with respect to the nail 20 may be preventedwith the screw alone.

The blade 34 may have a variety of configurations other thanspecifically described above. As noted, it is desired that the blade 34have one or more generally planar outer surfaces which meet at an angle.Other than the shapes described above, the blade may have a star, squareor triangular shaped perimeter. Of course, a wide variety of otherconfigurations may be provided.

The various components of the apparatus of the invention may beconstructed from a wide variety of materials. In a preferred embodiment,the material is selected to provide appropriate strength and stiffness,and be bio-compatible with a human, including a human's immune system.Preferably, the material is biologically inert and sterilizeable. Onepreferred material is stainless steel. Titanium, cobalt, chromium andother materials may be used.

FIGS. 7, 7A and 8 illustrate another embodiment of an apparatus fortreating a fracture of the distal femur. This embodiment apparatusincludes an intramedullary nail 120 and a first blade 134 a and a secondblade 134 b.

In general, the intramedullary nail 120 is similar to the intramedullarynail 20 described above and illustrated in FIGS. 2 and 3. In thisembodiment, however, the intramedullary nail 120 includes a passage 126which is generally oval in shape. The first and second blades 134 a,bare also configured similar to the blade 34 described above andillustrated in FIG. 4.

In this embodiment of the invention, the blade passage 126 and blades134 a,b are configured to cooperate so that the blades 134 a,b securelyengage the intramedullary nail 120 to prevent relative movement therebetween. Preferably, the relative movement which is resisted orprevented is relative rotational movement of either or both blades 134a,b with respect to the intramedullary nail 120.

In a preferred embodiment, the size of the passage 126 and the size ofeach blade 134 a,b is selected so that when a single blade 134 a,b islocated in the passage 126, that blade 134 a,b is freely moveable,including rotatable. However, the sizes of the blades 134 a,b andpassage 126 are selected so that when the second blade 134 a,b ispositioned in the passage 126 along with the first blade 134 a,b,rotation of the blades 134 a,b with respect to the intramedullary nail120 is resisted.

In one embodiment, the oval has a pair of foci which are located fairlyproximate to one another. The blades 134 a,b have a width which isnearly as great if not greater than their height. In one embodiment, thetotal height of the two blades 134 a,b stacked upon one another isapproximately the same as the height of the blade 34 illustrated in FIG.4, such that the size of the passage in the nail 120 in which the blades134 a,b are placed is not so great that the strength of the nail iscompromised.

Use of this embodiment apparatus is similar to that described above. Oneof the blades 134 a,b is extended through the passage 126. The secondblade 134 a,b is also extended through the passage 134 a,b. A screw orsimilar member is preferably again extended into the intramedullary nail120 for engaging one of the blades 134 a,b, generating a force whichfurther locks the blades 134 a,b in place and preventing rotational andaxial movement thereof.

An advantage of this embodiment apparatus is a secure locking structureand use of smaller blades, each of which alone is easier to manipulate.The arrangement of the blades 134 a,b and passage 126 is such that thefirst blade 134 a,b inserted into the passage 126 may be inserted in anyorientation and is freely moveable. The second blade 134 a,b is theninserted in a specific orientation to mate with the blade which wasfirst inserted, thus securing the blades 134 a,b. In addition, insertionof the first blade aids in stabilizing the position of the fracture.Then, after insertion of the first blade, further alignment of thefracture is possible before locking the position of the fracture byinsertion of the second blade.

In similar fashion to that described above, the intramedullary nail 120and the blades 134 a,b may have a wide variety of configurations. Forexample, a number of configurations of two or more blades may beprovided which cooperate with a passage as described above to achieve alocking effect. In one embodiment, the blades may have an “X” “+” “T” orother cross-section or a combination of these cross-sections, where thelegs of the blades abut to achieve the locking. Also, the shape of thepassage may vary. As noted, it is preferred that the shape and size ofthe passage and blades be chosen such that individual blades positionedin the passage are moveable (including rotatable), but whereby lockingis achieved when the second, third or other additional blade is locatedin the passage. For example, in one embodiment, the portion of eachblade which extends through the passage may be circular. Each blade mayinclude a cut-out, such that when the cut-outs are aligned, a bar may beextended along the length of the blades in the aligned cut-outs, lockingthe blades together.

In one variation of the invention, movement of the blade or blades maybe substantially limited by a locking pin. Referring to FIG. 8, apassage may be provided through the blade or blades, which passage(s)may be aligned with the passage at the proximal end of the nail. Insteadof providing a set screw, an elongate pin may be extended through thepassage in the nail and the passage in each blade. In a preferredembodiment, a locking passage extends through the nail at an opposingportion of the blade passage opposite the passage extending from theproximal end of the nail. The tip of the pin is extended into thisopposing passage, preventing movement of the pin and the blade throughwhich it extends. Again, the pin is preferably locked in position withthreads located thereon which engage threads in the passage at theproximal end of the nail.

Regardless of the shape of the portion of the blade(s) which engage thepassage 126, it is desired that at least a portion of the remainder ofthe blades 134 a,b be arranged to resist rotation of the femur withrespect to the blade(s).

In accordance with the present invention there is also provided a bladeguide 200. The blade guide 200 of the invention, including its use, willbe described with reference to FIGS. 9-13.

As illustrated in FIGS. 9-11, the blade guide 200 has a generally planarmounting portion 202. Referring to FIG. 11, the mounting portion 202 isgenerally “C” or “U”-shaped. In one embodiment, the mounting portion 202of the blade guide 200 includes a nail attachment portion 204, anextension 206, and a guide attachment portion 208. The nail attachmentportion 204 and guide attachment portion 208 extend generally parallelto one another, and are connected by the extension 206 extending therebetween.

A passage 210 is provided through the nail attachment portion 204,preferably near an end thereof opposite the extension 206. As detailedbelow, the passage 210 is adapted to permit attachment of anintramedullary nail 20 of the invention to the blade guide 200.

The nail attachment portion 204 has a length sufficient to extend from acenterline of a femur to a point exterior to the femur, as bestillustrated in FIG. 11. The extension 206 extends from the nailattachment portion 204 generally perpendicular to the nail attachmentportion 204. The extension 206 has sufficient length to extend outwardlyof the femur in a direction perpendicular to the nail attachment portion204 (i.e. to a medial or lateral portion thereof), as also illustratedin FIG. 11.

The guide attachment portion 208 extends perpendicular to the extension206, preferably in a direction back towards a femur (i.e. in the samedirection from the extension 206 as the nail attachment portion 204).

As best illustrated in FIGS. 9 and 10, a guide 212 extends from theguide attachment portion 208. The guide 212 preferably extends upwardlyfrom the guide attachment portion 208 generally perpendicular to a planein which the mounting portion 202 of the blade guide 200 is positioned.

As illustrated, the guide 212 is a generally rectangular body. Asillustrated, the guide 212 extends upwardly from the guide attachmentportion 208 at an angle θ. This angle θ is preferably less than 90degrees, and more preferably between 60 and 85 degrees. The exact angleis chosen so that a blade passage 214 is aligned with the blade passage26 in an intramedullary nail 20 located in the femur, as detailed below.

The blade passage 214 is provided through the guide 212 in a planeparallel to the mounting portion 202 of the blade guide 200. The bladepassage 214 is sized to permit passage of a blade of the invention therethrough under close tolerances. Of course, in an embodiment where thepassage 26 through the intramedullary nail 20 is at an angle other thanperpendicular thereto (such as 84 degrees) then the blade passage 214 issimilarly offset and not parallel to the mounting portion 202 (i.e.offset by 6 degrees in that case).

In general, the blade guide 200 of the invention is designed to aid inthe formation of a blade passage into or through a femur and location ofa blade in the passage or bone formed in the femur. More particularly,the blade guide 200 is designed for use in forming a blade passagethrough a femur in alignment with a blade passage through anintramedullary nail of the invention, and location of a blade or bladesin that passage and the nail.

Use of the blade guide 200 of the invention will be described withreference to FIGS. 12 and 13. In a preferred embodiment of theinvention, an intramedullary nail in accordance with the invention isplaced in a femur, such as in a manner described above. Reference isspecifically made to the embodiment nail 20 illustrated in FIGS. 2-6,though other devices may be used. As detailed above, and as illustratedin FIGS. 12 and 13, the nail 20 has a blade passage 26 extending therethrough.

The blade guide 200 of the invention maybe attached either beforeinsertion of the nail 20 or after insertion, preferably at the proximalend 22 of the nail. In one embodiment, the blade guide 200 is attachedto the intramedullary nail 20 with a screw or bolt 216. The screw orbolt 216 is adapted to pass through the passage 210 in the nail mountingportion 206 of the blade guide 200, engaging the blade guide 200 andthen the nail 20. As described above, in one embodiment, such as thatillustrated in FIGS. 3 and 7, the nail 20 includes a passage extendinginwardly from the proximal end 22 thereof, that passage being threaded.In one embodiment, the screw or bolt 216 may comprise the screw 40 whichis ultimately used to affix the blade to the nail 20, as illustrated inFIG. 6, or may alternatively comprise a different, similarly threadedscrew or bolt. In such an arrangement, the screw is first not threadedinto the blade passage 26, but only into engagement with the blade guide200 and nail 20.

As detailed above, when the nail 20 is inserted into the femur, such ispreferably done with the knee flexed or bent to permit access to theaxis of the femur. After the blade guide 200 is affixed to theintramedullary nail 20, however, the knee may be extended, asillustrated in FIGS. 12 and 13. At this time, the blade guide 200 isaffixed to the intramedullary nail 20 and extends from the femur withthe guide 212 at a location exterior to the femur. Furthermore, thepassage 214 in the guide 212 of the blade guide 200 is aligned with theblade passage 26 through the intramedullary nail 20, when consideringboth location and orientation.

In a next step, a passage is formed through the femur into which a blade34 or blades of the invention may be located. In one embodiment, smallpilot holes may be drilled through the femur by locating a drill bit ateach corner of the passage 214 in the guide 212, and then drillinginwardly through the femur. A punch may then be used to knock out theportion of the femur bounded by the pilot holes.

Of course, a wide variety of techniques may be used to form the bladepassage through the femur. Such techniques may include drilling,punching, boring or the like. In one or more embodiments, one or moreadditional templates may be connected to the blade guide 200 if aparticular portion of an area aligned with the passage 214 is to bedrilled or bored. Such templates are useful in aligning and stabilizinga drill bit or other member used to drill a portion of a femur alignedwith the portion of the passage 214. In one embodiment, one or moretemplates or the like may be placed into engagement with the passage214, each template having one or more smaller passages defined therethrough for accepting a drill bit or the like. Such templates are usefulin particularly locating a bit or the like for forming a passage.Preferably, the template is removable, so that once the passage in thefemur is formed, the blade may be passed through the passage in theblade guide into engagement with the femur.

It will be appreciated that because the passage 214 through the guide212 is aligned with the blade passage 26 through the intramedullary nail20, the blade passage formed by drilling, punching or the like isaligned through the femur with the blade passage 26 in the nail 20.

Once the blade passage is formed through the femur, the one or moreblades 34 of the invention may be located therein. The blade or blades34 are passed through the passage 214 in the guide 212 portion of theblade guide 200. Once positioned in the femur and the blade passage 26through the intramedullary nail 20, the blade(s) 34 may be affixed tothe nail 20 in a manner described above. For example, the screw 40(which may also comprise the screw 216) may be threaded inwardly intoengagement with the blade(s) 34, locking it (them) in position.

After placement of the blade(s) 34, the blade guide 200 may be removedfrom the nail 20.

It will be appreciated that the exact configuration of the blade guide200 depends substantially upon the configuration of the intramedullarynail to ensure alignment of the passages to be formed. For example, asthe angle of the bend in the intramedullary nail 20 (angle β asillustrated in FIG. 3) varies, so must the angle of the guide 212portion of the blade guide 200 and/or the location of the passage 214therein.

In an embodiment where the blade passage 26 through the intramedullarynail 20 is tilted (such as at an angle α as illustrated in FIG. 5), thenthe passage 214 through the guide 212 portion of the blade guide 200 issimilarly oriented.

The exact shape and size of the passage 214 is preferably dependent uponthe shape and size of the blade or blades which are to be placed. Thus,the size and shape of the passage 214 may be dictated in a similarmanner to the passage 26 described above with respect to theintramedullary nail 20.

Preferably, the blade guide 200 is made of a similar material as thenail 20, such as an inert, sterilizeable material. At least the portionof the blade guide 200 surrounding the passage 214 is preferablyconstructed of a very durable material so as to prevent damage theretowhen drilling or punching.

In one embodiment, the blade guide 200 is constructed as a single orunitary element. In one or more embodiments, the blade guide 200 maycomprise multiple elements which are connectable. In one embodiment, therelative location and/or orientation of the portions of the blade guide200 may be adjustable. In this manner, the blade guide 200 may beadapted for use in a variety of different situations, such as toaccommodate differing sizes and shapes of femurs. In one embodiment, theguide 212 portion of the blade guide 200 may be removable, and more thanone guide 212 may be provided. One guide 212 may have a plurality ofpassages there through or a collet or the like for aligning drill bits.Another guide 212 may then have a blade aligning passage for insertionof the blade(s) into the femur.

It will be appreciated that the exact order of the steps of themethod(s) described herein may vary. For example, it is possible to usethe blade guide 200 to form the passage in the femur and then remove theblade guide 200 before placing the blade(s).

As stated, the first or mounting portion 202 of the blade guide 200 ispreferably generally planar and relatively thin. This constructionallows the knee to be extended even when the blade guide 200 isconnected to the intramedullary nail 20. This is important, for when theknee is extended, more accurate alignment of the femur, nail and guidemay be achieved.

It will be understood that the above described arrangements of apparatusand the method therefrom are merely illustrative of applications of theprinciples of this invention and many other embodiments andmodifications may be made without departing from the spirit and scope ofthe invention as defined in the claims.

1. An apparatus for treating a fracture of a femur comprising: anintramedullary nail configured for location in the intramedullary spaceof said femur, said intramedullary nail having a proximal end and adistal end, said intramedullary nail defining a blade passage extendingthere through, said blade passage located in a portion of saidintramedullary nail proximal to said proximal end of said intramedullarynail; and at least a first blade and a second blade, said at least onefirst and second blades configured to extend through said blade passage,said at least one first and second blades when positioned in said bladepassage alone permitted to rotate with respect thereto, and wherein whensaid at least one first and second blades are positioned in the bladepassage at the same time, rotation of said at least one first and secondblades relative to said intramedullary nail is resisted.
 2. Theapparatus in accordance with claim 1 wherein said at least one first andsecond blades each have an “I”-shaped cross-sectional shape.
 3. Theapparatus in accordance with claim 1 wherein said intramedullary nailincludes a locking screw passage extending from said proximal end tosaid blade passage.
 4. The apparatus in accordance with claim 3 whereinan axis extends along said intramedullary nail from its proximal to itsdistal end and said locking screw passage extends along at least aportion of said axis.
 5. The apparatus in accordance with claim 1including a locking screw configured to engage said locking screwpassage and one of said blades when said at least one first and secondblade are located in said blade passage.
 6. The apparatus in accordancewith claim 5 wherein said at least one first and second blades have apassage for accepting a portion of said locking screw.
 7. The apparatusin accordance with claim 1 wherein said blade passage has a generallyoval cross-sectional shape.
 8. The apparatus in accordance with claim 1including at least one passage through said intramedullary nail at saiddistal end thereof configured to accept a screw.